1. Field of the Invention
This invention relates to a braiding machine and, more specifically, to such a machine which includes a circular array of outer strand supply bobbins which move in one direction, a circular array of inner strand supply bobbins which move in the opposite direction and an oscillating device for directing the outer strand inwardly and outwardly of the inner strand supply bobbins to form a completed braided product or to provide a braided jacket for a core member being drawn through the machine.
2. Description of the Prior Art
There have heretofore been provided a number of braiding machines which are employed to braid a plurality of strands into a combined work product. Some of these machines include mechanisms for directing a plurality of strand supply bobbins inwardly and outwardly of each other through elaborate gearing and camming means. The gearing and camming means are quite complicated to manufacture and maintain and tend to limit the speed at which braiding can be accomplished. There are, however, other commonly used types of braiders which include a plurality of inner bobbins and a plurality of outer bobbins which are caused to rotate in opposite directions while the strand from the outer bobbin is directed inwardly and outwardly of the array of inner bobbins to produce the braiding. It is these latter types of machines to which the present invention is directed.
To direct the outer strands inwardly and outwarly of the inner strand bobbin a number of machines, such as those disclosed in U.S. Pat. Nos. 647,410, 814,711 and 1,660,049 and British Pat. Nos. 13,560 and 109,180, have used an oscillating strand guide of one form or another. U.S. Pat. No. 647,410 and British Pat. No. 13,560 employ a cam track and U.S. Pat. No. 814,711 employs a rotating cam to produce the desired movement of the guide. Although a camming means can be effectively utilized to control the guiding path of the strand inwardly and outwardly of the bobbins, they tend to be more susceptible to wear and are often more complicated to lubricate. British Pat. No. 109,108, on the other hand, employs a simple crank linkage on a large gear member to produce a simple sinusoidal guiding path. The larger gear mounting and driving structure appears to significantly add to the overall weight and size of the machine and to generally prevent horizontal orientation of the machine's axis. The oscillating guide means of U.S. Pat. No. 1,660,049 is driven by an air actuated means complicating the machine's support requirements.
Accordingly, another form of braiding machine was alernatively employed in an effort to eliminate some of these problems and was of the type generally disclosed in U.S. Pat. Nos. 958,512; 1,059,523; 1,888,477; 1,955,206 and 1,981,377. Like the machines of the patents cited hereinabove, each of these machines must include structure and means for mounting an array of outer strand supply bobbins and an array of inner strand supply bobbins and for causing relative opposite circular movement thereof. The means for driving each of the inner strand supply bobbins must be of a form which will allow the outer strand to be directed inwardly and outwardly of the array of inner strand supply bobbins in a manner which will produce braiding. In this latter group of machines a pair of rotating dogs are employed for this driving means and are adapted to ensure that at least one of the dogs will be engaged with its respective inner strand supply bobbin to provide driving force thereto as the other dog is sufficiently displaced therefrom to allow passage of the outer strand inwardly of the bobbin. However, to ensure that the outer strand will be directed inwardly and outwardly of the inner strand supply bobbins, these prior art devices include a camming surface fixedly mounted relative to each inner bobbin for predetermined deflection of the outer strand inwardly and outwardly thereof. The utilization of a camming means of this type has generally limited the speed at which these braiding machines can be operated. The resulting transverse frictional force which the camming surfaces produce on the strand as the speed of the braiding machine increases tends to wear out the strand and cause it to break or produce a drag on the strand which will cause it to become fouled in other regions of the machine. Nevertheless, although there is no detailed disclosure of the strand guiding system, it appears that some machines, such as the one disclosed in U.S. Pat. No. 3,756,117 are still being introduced which rely on this limited method of strand guiding.
It can generally be said of the prior art machines described hereinabove that they each rely upon one or more features which tend to limit the speed at which the machine can be operated, increase the overall size and weight of the machine, decrease the number of strands that can be braided or limit the size of strand supply bobbins which can be utilized.